Cornering and Braking technique... cont'd

bloaker

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#1
Taken out of context of the Decending thread.
I figured a whole thread could be dedicated to this....

Perhaps tangential to the topic, but I am interested in discussion of cornering and braking techniques when descending.
I feel this is a downfall of most cyclist I rode with back home.
Diminishing/Constant/ and Expanding radius corners all allow for different speeds.
Diminishing corners have a late apex, and it is exaggerated on a downhill.
Constant radius corners are the most predictable allowing you to spit the middle.
And Expanding radius corners have an early apex and allow you to get the bike turned well before you see any 'danger' that might make you apprehensive.

In all corners, if you guess wrong then you lose momentum - and if you loose a couple kph at the top of the hill, it equals much more by the bottom.

While I do not race, many friends I rode with back in VA did - and with just casual observation, my friends that are Cat3 are much smoother in a corner than my friends that are Cat5. I think it truly comes down to looking through a corner and understanding the apex allowing you to carry the maximum corner speed. Corner speed = exit speed. And on a downhill, you will accelerate after a corner, so every kph you have at the exit significantly increases your top speed further down.

With speed comes the desire to turn in early - Early apex pushes you out wide on exit. Scary through when your option is a cliff or a mountain on the outside of the road.

Late apex allows you to square off the corner, but requires you to scrub speed. - if you are hella string, maybe this could be an advantage, but truth be told, you probably just blew the corner.
Obviously the sweet spot is in the middle - and in a racing situation, if in a pack, you have little choice.

Playing video games (my choice was MotoGP3) can help you recognize these subtle differences.

My fear - even as a non racer is the camber of the road. If a road pitches off camber as you are in a corner, the bike may not go where you thought it was going to go.

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As for the best tire pressures on Handling vs speed... I defer as I truly do not have an intimate enough relationship with my bicycle to tell the difference in 5lbs of air pressure.

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I opened the can of worms.... discuss!
 
Sep 2, 2009
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#2
I find that trust in the equipment really aids speed; being able to accurately predict the power of braking, and also how far you can lay the tyres down adds so much.
 

bloaker

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#3
trusting your equipment is a must as confidence is the only way to ever truly go fast.

But knowing and understanding the limit of your equipment - traction in a corner / pedal strike vs lean angle / etc... is vital. And the only way to know is to ride.

My Opinion and Experience:
I feel many people can spin. Many can sprint (not Me tho). Many people can point and go... this is a result of long training rides that require little bike handling skills, just strength and endurance.

Bike handling skills comes from getting out of your comfort zone from time to time. Taking the ride with sharp turns and steep descents requiring more attention to be paid to braking rather than 'going' - this is somewhere many friends never train.

I spent years on a motorcycle on the racetrack - there are things completely unrelated and things I feel are exactly the same. Physics - the same.
The problem is this... no two corners are the same. So it is best to practice all kinds - IMO.

The nice thing about a racetrack, I got to see the same corner over and over again ever 100 seconds or so (depending on the track). You get to understand that particular track and how to connect the dots of exiting one corner to entering the next. You need to know where to go slow to actually be faster. In a crit - this may relate. You can turn in a little later on the next lap and see your bike angle and feel the traction... if it is there and solid, you can then go a 'little' harder the next time. Over the course of a race, you find where you can go deeper into corners to overtake an 'early braker'

In the case of a downhill, by the time you finish descending, your desire to climb the same hill may be diminished. That makes practice a bit harder.
 
Apr 3, 2012
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Tama Center <-> Otemachi
#4
On public roads, not knowing the road conditions up ahead would call for a conservative line. The fear of rocks, leaves, or a car keeps me at a speed and line that will let me escape. Even straight line at speed isn't safe. I've T-boned a taxi that burst out of a side street. Take it to the track, or a closed course.
 
Sep 2, 2009
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#5
Was more thinking along the lines of 'what is your preferred braking and cornering practice, when you are descending fast' kind of discussion, but on you go.
 

bloaker

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#6
Three kinds of corners as I stated. Diminishing. Constant, Expanding.
I am not a racer, but on a downhill I like to get aggressive.

Diminishing, I like to shift early, brake early, release the brake and let the bike roll the corner to keep the bike stable mid corner. Diminishing corners require more lean angle and the bike is most likely to get upset by additional inputs. Keep the eyes through the corner and pedal when the angle guaranteeing there will be no strike.

Constant, I like to brake late, throw the bike through the corner and jump on the pedals as soon as possible.

Expanding, usually does not require a shift, but rather feathering of the brake and it has the least amount of lean angle - so you have the most room for a mistake.

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Is this the type response you were looking for?
 
Sep 2, 2009
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#9
LOL. This isn't JapanToday mate.

For the record, thanks for the comment; was interesting. I find on super fast descents I brake before the corner, to skim off speed, then carve through it with no braking. Seems the smoothest and best feeling method. Did the same when I was an XC MTB shredder, back in the late 90s.
 

bloaker

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#10
Haha -

The braking method you mention is the same I do for Diminishing radius turns.
And it is the same you need to do for the video games.

LOL. This isn't JapanToday mate.

For the record, thanks for the comment; was interesting. I find on super fast descents I brake before the corner, to skim off speed, then carve through it with no braking. Seems the smoothest and best feeling method. Did the same when I was an XC MTB shredder, back in the late 90s.
 
Sep 2, 2009
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#11
Haha,

Yeah, I like it the best. The more time off the brakes when cornering the more swwoooooosh I get.

Feathering the brakes when going through the middle of the corner always feel dodgy to me (it is the kind of thing I do when I suddenly see a car coming the other way and I am on their side of the road). I am always thinking that if my wheels leave the ground, and I have my brakes on, the wheels will lock, then start skidding when they land. This is a laugh on an MTB off road, but heart stopping when dive-bombing down the side of a mountain.
 

trad

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#12
for me.. brake late, brake straight; learn to avoid (or correct) the dreaded shimmy, put weight on ouside crank; learn/practice countersteer (also teaches you to not lean body too much); ALWAYS look thru corners and where you want to go; avoid passing your mate down hil unless you can clear his/her line safely and you know how they might react to you; relax (esp your arms) and feel the "flow" when it all comes togther.

best practice IMO is to practice descending on mtn bike or CX; or to follow a better descender.
 

Sikochi

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Sep 13, 2010
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#13
learn to avoid (or correct) the dreaded shimmy,
As a precaution, I usually press the legs against the toptube to prevent any wobbling. Last two days on the mama chariot had slight climbing (up to 100m) and I was doing this on the descent...except the mama chariot has no toptube :eek:

avoid passing your mate down hil unless you can clear his/her line safely and you know how they might react to you
Did this Saturday: moved up on the outside of the rear cyclist (of 2), they were descending so moderately that I was having to overbrake all the time - and the rear guy half panicked. Note to cyclist: I`m not going to cut you up/steal your line. I apologised, but when descending....be aware of what is behind you! :gun:

***
There was a thread about descending/cornering a while ago, and whilst I am a serial knee-out person, I have been following Jobst Brandt`s advice about not doing this, and I can see his point about it giving more control and allowing you to corner faster. Trouble is, on bad road surfaces I don`t like leaning the bike much...:eek: His articles are here:-
http://www.bicyclesource.com/descending_and_cornering
http://sheldonbrown.com/brandt/descending.html
 
Aug 27, 2012
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#14
It has always been my understanding to brake on the straight and never on the turn. Now that doesn't account for (my) human fear in the middle of a turn ("Oh 'ek I need to scrub some speed off or I'm going to ayeeeeee:eek:), but the simple physics explained to me were that you can always turn better when the wheel is still fully in contact with the road - the minute you brake you could cause the wheel to lose traction with the road surface and once it starts to do that momentum takes over from turning (so lose front wheel traction and you plough-on forwards, lose rear traction and the back drifts out causing oversteer on motorbike/car but on a bike is more likely to cause major instability which all-except-the-best overcorrect and :eek:uch:)

So brake before turn, turn in for the apex, let momentum carry you through the turn.
 
Aug 27, 2012
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#15
I would add two points to my reply above
i) As has been remarked above, most of the time we're having to account for cars, etc on open public roads which means you don't really get to use "the apex" as you are hugging the left hand side of the road and forced to follow its multi-micro corners-within-a-corner which in turn results in us effectively having to do "multiple" turns rather than one smooth turn
ii) Delighted I finally got to use the :eek: smilie in a post; never thought I would
 

GSAstuto

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#16
Actually it's faster on a roadbike to brake late and continue braking just before the apex. This 'settles' the bike and gives a bit better 'turn in' . How you balance front and back is very important -so you need to have good practice on modulation. A pedal bike has literally no power through a corner except by momentum, if you 'give up' all that before the corner, then you have nothing to work with IN the corner. Excepting for shallower corners that you could pedal through, or steep ones that you'll pick up a little more speed due to gravity. But nothing like a motorbike or car... they are completely different animals.
 

AlanW

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#17
I agree with Tim about the braking through the first part of the turn - but it does take practice and the ability to judge the corner severity vs. your tyres grip on the road, which of course varies with different conditions, surfaces and cambers.

As far as the line through the corner goes: early apex is a big no-no as shown in this diagram.

proxy.php?image=http%3A%2F%2Fwww.modernracer.com%2Ftips%2Fproperapex2.jpg&hash=403b183861ec30a2fe552047a34c0318


At best you'll have to scrub off a lot of speed, at worst, well.....you can see where the line is heading :(
 

bloaker

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#18
Alan, this is right along the lines of the Diminishing, Constant, Expanding radius corners I was talking about.

I believe a lot of people do not understand the very concept the drawing shows. Early apex = wide exit.